The present invention concerns salts from new aryl-alkyl-substituted imidazolium and triazolium cations and any anions. The invention concerns furthermore methods for the chemical reaction and separation of substances comprising the inventive salts as solvents, solvent additives, or extraction agents as well as the use of the inventive salts, for example, as Solvents or solvent additives in chemical reactions, as extraction agents for the separation of substances or for the storage of hydrogen.
Nowadays, organic solvents find applications in many different areas, beginning with chemistry, but also in biology and in material development. However, in traditional catalytic processes organic solvents as a result of their volatility, flammability and toxicity often bring about the problem that dangers relating safety, health and environment must be prevented with costly technical measures (cf. Wasserscheid/Welton, “Ionic liquids in synthesis”, Wiley-VCH 2007).
Hence, new environmentally friendly synthesis methods that require no solvents or use environmentally friendly alternative solvents become more and more important. In this context, attention has focused in recent years particularly on ionic liquids.
The definition of ionic liquids (“ionic liquids”, “ILs”) concerns substances that consist completely of organic cations and organic or inorganic anions and have, in addition, a low melting point of less than 100° C. and a relatively low viscosity.
Ionic liquids exhibit further advantageous properties, for example, low vapor pressures, low combustibility as well as an adjustable polarity and miscibility with other organic and inorganic substances. Hence, they represent in synthesis and homogeneous catalysis an interesting alternative to the organic solvents used today. The low vapor pressure, the low flammability linked therewith, the low toxicity and variability of these compounds makes them ideal “green” solvents for a plurality of chemical processes.
Known ionic liquids contain as a cation, e.g., alkyl ammonium, alkyl phosphonium, N,N′ dialkyl imidazolium and N-alkyl pyridinium cations:

Up to now, however, there is no reliable way to predict the melting points of organic salts. Discovering new organic salts that fulfill the definition of ionic liquids is possible currently only experimentally.
The electronic properties of the conventionally employed ionic liquids available commercially can be changed only minimally.
From the prior art (e.g., WO 03/074494 A1, DE 10 2004 060 247 A1 or EP 1 201 657 A1) N,N′-substituted imidazolium and triazolium salts are known which are used as ionic liquids. The individual compounds disclosed therein are aliphatic substituted imidazolium and triazolium salts in which the sp3-hybridized substituents on the nitrogen atoms reduce the possibilities of influencing the system to the inductive effects. Mesomeric effects cannot be used.
Presently, the research activities focus extensively on the synthesis of new anions. Thus, WO 03/074494 A1 discloses ionic liquids with anions free of halogen; WO 2007/131498 A2 discloses hydrophobic anions; WO 2004/054991 A1 discloses those with [N(CF3)2−] anions, EP 1 512 460 A1 those with thiocyanate anions; and WO 2004/096776 A1 those with alkyl sulfate anions.
It is therefore the object of the invention to provide salts with new organic cations whose electronic properties can be varied in a targeted fashion and whose melting points and solution properties are adjustable so that they are suitable for use as ionic liquids.